Method and system for system information acquisition in wireless communication system

Disclosed is a method that decodes a broadcast channel to obtain first system information periodically broadcasted from a base station; applies at least one cell selection parameter indicated in the first system information to camp on a cell served by the base station and storing the first system information; accesses the camped cell based on at least one random access parameter indicated in the first system information; and determines whether at least one of a system information block of second system information available in the camped cell is provided based on at least one of the periodic broadcast and an on-demand basis. The on-demand basis to deliver the corresponding system information block of the second system information available in the camped cell is decided based on at least one of an indication and a flag included in the first system information for the system information block.